Method of assembling electronic component

ABSTRACT

A method of assembling an electronic component, such as a ladder-type filter, having at least one element being held between terminal plates under pressure and stored in a case. First, the terminal plates are inserted in a cavity of a base so as to align the terminal plates along a direction of thickness thereof. Then, the element is inserted between the terminal plates in the cavity, and a spring plate is inserted in the cavity at an outside of one of the terminal plates. Thereafter, all parts inserted in the cavity are compressed by a presser along the direction of thickness so that an overall thickness of the parts is smaller than an inner size of the case. Then, the case is set on the base, and all parts are inserted from the cavity into the case simultaneously. Electrode surfaces of the element are not damaged since they are not in sliding contact with the terminal plates, and working efficiency is improved by this compressed insertion.

BACKGROUND OF THE INVENTION

The present invention relates to a method of and an apparatus forassembling an electronic component, such as a ladder-type filter, havingat least one element being held between terminal plates under pressureand stored in a case.

FIGS. 1 and 2 show a conventional four-element ladder-type filter. Thisfilter comprises two series ceramic resonators 2 and 3, two parallelceramic resonators 4 and 5, an input terminal plate 6, a ground terminalplate 7, an output terminal plate 8, an internal connection terminalplate 9 and a plate spring 10, which are stored in a box-type case 1.Outlines of these inner parts are substantially equivalent to eachother. FIG. 3 is a circuit diagram showing the electrical connectionthereof.

The input-terminal 6 is provided on its one major surface with aprotruding portion 6a which is in pressure contact with a centralportion of the series resonator 2. The ground terminal 7 is provided onits both major surfaces with protruding portions 7a and 7b which are inpressure contact with central portions of the two parallel resonators 4and 5 respectively. The output terminal 8 is provided on its both majorsurfaces with protruding portions 8a and 8b which are in pressurecontact with central portions of the parallel resonator 5 and seriesresonator 3 respectively. The internal connection terminal 9 has aportion 9a which is inserted between the series resonator 2 and parallelresonator 4, a portion 9b which is arranged next to an outer majorsurface of the series resonator 3, and a coupling portion 9c whichconnects these portions 9a and 9b. Since the plate spring 10 isinterposed between the portion 9b and an inner side surface of the case1, the terminals 6-9 and the resonators 2-5 are in pressure contact witheach other to be electrically connected.

A cover sheet 11 is inserted in an opening of the case 1, and a cavitywhich is defined by the cover sheet 11 and the opening is filled up withfiller 12 such as resin, thereby the opening of the case 1 is sealed.Lead portions 6b, 7c and 8c of the input terminal 6, the ground terminal7 and the output terminal 8 protrude from the opening of the case 1.

In the conventional ladder-type filter having the aforementionedstructure, the resonators 2-5 utilizing surface-directional spreadingvibration mode are merely in point contact with the terminals 6-9 at thecentral protruding portions 6a, 7a, 7b, 8a and 8b. Therefore, it isnecessary to manually insert the resonators 2-5 and the terminals 6-9into the case 1 one by one with tweezers since these parts easily getslant due to the point contact. As a result, working efficiency ofassembling operation became quite low. Further, since it is necessary tobring all parts into close contact with each other in the final stage ofassembly, much time is required for inserting the final part into a verysmall clearance. Moreover, electrode surfaces of the resonators 2-5 maybe damaged by the assembling operation.

Thus, the conventional method of assembling electronic component such asa ladder-type filter had a problem of low working efficiency caused bymanual assembly.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to provide a methodof and an apparatus for assembling an electronic component, by which theworking efficiency can be improved.

Another object of the present invention is to provide a method of and anapparatus for assembling an electronic component, by which the electrodesurfaces of the element will not be damaged in assembling operation.

In the method of the present invention, first the terminal plates areinserted in a receiving portion of a base means so as to align theterminal plates along a direction of thickness thereof. Then, theelement is inserted between the terminal plates in the receivingportion. If the terminal plates are inclined or slanted in the receivingportion, the element cannot be smoothly inserted between the terminalplates. Therefore, the base means may preferably be provided with leadportion receiving holes on a bottom of the receiving portion so as tohold the terminal plates self-sustainably. Also, a spring plate may beinserted in the receiving portion at an outside of one of the terminalplates. Thereafter, the terminal plates and the element are compressedalong the direction of thickness. On the other hand, the case is carriedto the base means, and set on the base means so that an opening of thecase corresponds to the receiving portion. Then, the terminal plates andthe element are inserted from the base means into the casesimultaneously.

According to the present invention, inner parts such as the terminalplates and the element are assembled in the base means first, and thenthese parts are compressed and inserted into the case all at once. Bythis compressed insertion, the assembling efficiency is highly improvedas compared with the one-by-one insertion.

Moreover, since all of the inner parts are inserted into the casesimultaneously, they are not in sliding contact with each other, wherebythe electrode surfaces of the element are not damaged and reliability isimproved.

Further, since the operations such as assembling the inner parts in thebase means and inserting the inner parts into the case can be carriedout automatically, the working efficiency is highly improved as comparedwith the manual assembly.

The foregoing and other objects, features, aspects and advantages of thepresent invention will become more apparent from the following detaileddescription of the present invention when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view showing a conventional four-elementladder-type filter;

FIG. 2 is an exploded perspective view of the filter shown in FIG. 1;

FIG. 3 is an electric circuit diagram of the filter shown in FIG. 1;

FIG. 4 is a perspective view showing a pallet;

FIG. 5 is a partially enlarged perspective view showing the pallet shownin FIG. 4;

FIG. 6 is a perspective view showing a chuck hand;

FIG. 7A is a perspective view showing an element-supply unit;

FIG. 7B is a sectional view showing an element-supply unit shown in FIG.7A;

FIG. 8 is a perspective view showing an assembly jig;

FIG. 9 is a plan view showing the assembly jig receiving terminalplates;

FIG. 10 is a perspective view showing an operation for inserting aresonator between terminal plates;

FIGS. 11A and 11B are plan views showing an operation for inserting aresonator between terminal plates;

FIGS. 12A and 12B are sectional views of the assembly jig showing anoperation for inserting parts in a case;

FIG. 13 is a perspective view showing an assembly jig according to asecond embodiment of the present invention;

FIG. 14 is a plan view of the assembly jig shown in FIG. 13 receivingterminals and resonators;

FIG. 15 is a perspective view showing an assembly jig according to athird embodiment of the present invention; and

FIGS. 16A, 16B, 16C and 16D are plan views of the assembly jig shown inFIG. 15 receiving terminals and resonators.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 4 and 5 illustrate an exemplary pallet P which is employed in thepresent invention. This pallet P is a plate which has a number ofcavities P₁ -P₆ on an upper surface thereof for receiving respectiveparts separately in constant arrangement. The internal connectionterminal plate 9, the input terminal plate 6, the ground terminal plate7, the output terminal plate 8, the plate spring 10 and the case 1 asshown in FIGS. 1 and 2, are inserted and vertically held in the cavitiesP₁ -P₆ respectively. When the parts are thus inserted in this pallet P,upper halves of the parts protrude from the upper surface of the palletP.

FIG. 6 shows a chuck hand 21. The chuck hand 21 is used to chuck theterminal plates 6-9, the case 1 and the plate spring 10 from the palletP to insert them into an assembly jig 31 as described later one by one,and is used to chuck the resonators 2-5 from an element supply unit 30as described later to insert them into the assembly jig 31 one by one.The chuck hand 21 has a fixed pawl 40 for holding one major surface ofeach part such as the resonator and the terminal plate, a first movablepawl 41 which moves along the direction B₁ for holding the other majorsurface of each part, a second movable pawl 42 which moves along thedirection B₂ perpendicular to the direction B₁, and an insertion pusher43 which is movable in the vertical direction B₃. The fixed pawl 40 isprovided with a stopper surface 40a for positioning a rear edge of eachpart, and a vertical groove 40b which can be passed through by thepusher 43. The first movable pawl 41 is also provided on its innersurface with a vertical groove 41a corresponding to the groove 40b. Thesecond movable pawl 42, which is used to push a front edge of each partagainst the stopper surface 40a of the fixed pawl 40 for correctlypositioning the part, has a wedge-shaped cross-sectional surface. Thesecond movable pawl 42, which extends downwardly beyond the pawls 40 and41, also serves as a guide for inserting the resonators 2-5 between theterminals 6-9, as hereinafter described. The pusher 43 is used todownwardly push each part, which is chucked by the three pawls 40, 41and 42.

As shown in FIGS. 7A and 7B, the element-supply unit 30 comprises a body50 and a plurality of cassettes 51 which stand uprightly on the body 50,and a pusher 52 which moves along the direction C₁. A number ofresonators 2-5 of the same type are stacked in each of the cassettes 51.First, resonators 2-5 come down from lower ends of the cassettes 51 infront of the pusher 52, and then are pushed forwardly one by one by thepusher 52 to the forward end of the body 50. Next, the resonators 2-5are sucked by a vacuum suction member 53 so as to be upwardly rotatedabout an axis 53a by about 90 degrees. Thereafter, the resonators 2-5are chucked by the chuck hand 21, and carried into the assembly jig 31.When the cassettes 51 are vacated, they can be easily exchanged by newones.

As shown in FIGS. 8 and 9, the assembly jig 31 is provided with a base60 having a cavity 61 on an upper surface thereof for receiving theinner parts such as the resonators. The depth of the cavity 61 is set tobe longer than half of the height of these inner parts and shorter thanthe height thereof. The jig 31 is also provided with a presser 62 whichis movable along a horizontal direction D₁ so that a head portion 62a ofthe presser 62 is arranged on one end of the cavity 61. The head portion62a of the presser 62 has an escape groove 62b on forward end surfacethereof. An ejector 63 which is vertically movable along a direction D₂is arranged at a central portion of a bottom of the cavity 61. Also,lead portion receiving holes 64a-64c which extend vertically are formedon the bottom of the cavity 61 beside the ejector 63, and are providedwith tapered openings at the top thereof. Therefore, the terminals 6-8are held self-sustainably in the cavity 61 when lead portions 6b, 7c and8c of the terminals 6-8 are inserted in the holes 64a-64c respectively.An concave portion 65 is provided on one side surface of the cavity 61to locate the coupling portion 9c of the internal connection terminal 9.The terminals 6-9 are located on constant positions by inner sidesurfaces of the cavity 61, the holes 64a-64c and the escape portion 65.

An operation for assembling the respective parts in the assembly jig 31is now described.

First, the terminal plates 6-9 which are taken out from the pallet P bythe chuck hand 21 are inserted in the cavity 61 of the assembly jig 31one by one (see FIG. 9). Then the resonators 2-5 which are carried fromthe element-supply unit 30 by the chuck hand 21 are inserted between theterminals 6-9 one by one. In particular, as shown in FIG. 10, theresonators 2-5 are laterally inserted between the terminals 6-9 alongthe upper surface of the base 60, and then the resonators 2-5 aredownwardly pushed by the pusher 43 when they reach the positioncorresponding to the cavity 61. At this time, the terminals 6-9 whichare already assembled in the assembly jig 31 self-sustainably may beslightly inclined or slanted so as to hinder the insertion of theresonators 2-5. However, since the second pawl 42 of the chuck hand 21having a wedge-shaped section separates the terminals 6-9 from eachother as shown in FIGS. 11A and 11B, it is possible to smoothly insertthe resonators 2-5 between the terminals 6-9. When the resonators 2-5are inserted, electrode surfaces thereof are not damaged since nocompressive force acts between the terminals 6-9. After the resonators2-5 are inserted in the aforementioned manner, the plate spring 10 isinserted in a clearance between the portion 9b of the terminal 9 and thepresser 62.

After all parts are assembled in the cavity 61 of the assembly jig 31,the parts are sidewardly compressed by the presser 62 as shown in FIG.12A, so that the overall thickness of the parts is smaller than theinner size of the case 1. Then, the case 1 is carried from the pallet Ponto the assembly jig 31 by the chuck hand 21, and located on a positionfor covering all parts which are projected on the base 60. Then, theejector 63 is upwardly moved as shown in FIG. 12B so as tosimultaneously insert all parts in the case 1. At this time, the partsare smoothly inserted due to an inclined surface la which is formed inan opening of the case 1. Further, the electrode surfaces of theresonators 2-5 are not damaged since the resonators 2-5 are not insliding contact with the terminals 6-9.

After the inner parts are inserted in the case 1 in the aforementionedmanner, the case 1 which is chucked by the chuck hand 21 is carried tothe cover sheet fitting unit (not shown), so that the cover sheet 11 isfitted into the opening of the case 1. After the cover sheet 11 isfitted into the case 1, an assembled product is carried to a nextsealing step, where the opening of the case 1 is sealed with resin 12 toobtain a final product.

FIGS. 13 and 14 show an assembly jig 700 according to a secondembodiment of the present invention. Inner parts which are assembled bythe jig 700 are identical to those of the first embodiment.

Referring to these figures, the assembly jig 700 is provided with a base70 having a cavity 71 on its upper surface for receiving inner parts.The cavity 71 has an opening 71a at one side portion. The jig 700 isalso provided with a positioning plate 72 which is horizontally slidablealong a direction D₃ for closing the opening 71a. The plate 72 has anescape portion 72a on a lower portion of its inner side edge in order toescape an interference with the coupling portion 9c of the internalconnection terminal 9.

The presser 73, the ejector 74 and the lead portion receiving holes 75aand 75b are similar to those shown in the first embodiment.

According to this embodiment, inner parts such as terminals 6-9 andresonators 2-5 are first inserted in a cavity 71 when the opening 71a isopened. Next, the plate 72 is inwardly slid to close the opening 71a soas to press side portions of the inner parts (excluding the terminal 6and the resonator 2) against an inner side surface 71b of the cavity 71.Therefore, the inner parts are positioned in the lateral direction asshown in FIG. 14. In this way, it is possible to smoothly insert theinner parts in a case 1.

FIGS. 15-17 show an assembly jig 800 according to a third embodiment ofthe present invention.

Referring to the figures, the assembly jig 800 is provided with a base80 having a pair of fixed guides 81 and 82 protruding thereon. A firstpositioning plate 83 which is horizontally slidable along a direction D₄on the base 80 is arranged at one side between the guides 81 and 82. Asecond positioning plate 84 and a third positioning plate 85 which arehorizontally slidable along a direction D₅ independently are arranged atthe other side between the fixed guides 81 and 82. The thickness of thefirst plate 83 is equivalent to the height of the fixed guides 81 and82, while the second and third plates 84 and 85 have substantiallyequivalent thicknesses, the sum of which is equivalent to the thicknessof the plate 83. The second plate 84, which is arranged under the thirdpositioning plate 85, is provided on its inner side edge withcomb-shaped terminal receiving grooves 84a-84e. The second plate 84 isalso provided on a lower portion of its inner side edge with an escapeportion 84f in order to escape an interference with the coupling portion9c of the internal connection terminal 9.

The presser 86, the ejector 87 and the lead portion receiving holes 80a,80b and 80c are similar to those shown in the first embodiment.

The operation of this embodiment is now described.

First, as shown in FIG. 16A, the first plate 83 is advanced while thesecond and third plates 84 and 85 are kept at retracted positions. Theinternal connection terminal 9 is inserted in a cavity which is definedby the first plate 83, the fixed guide 81 and a presser 86.

Next, the second plate 84 is advanced so as to push the internalterminal 9 against the first plate 83 as shown by two-dot chain lines inFIG. 16A. Thus the terminal 9 is held between the first and secondplates 83 and 84, so as to be positioned in a lateral direction. At thistime, the terminal receiving grooves 84b and 84e of the second plate 84are engaged with the portions 9a and 9b of the terminal 9, so as toposition the terminal 9 also in the direction of thickness.

Then, as shown in FIG. 16B, an input terminal 6, an ground terminal 7and an output terminal 8 are inserted one by one self-sustainably suchthat lead portions 6b, 7c and 8c of these terminals 6-8 are inserted inlead portion receiving holes 80a-80c provided on an upper surface of thebase 80. At this time, side edge portions of the respective terminals6-8 are held by the terminal receiving grooves 84a, 84c and 84d of thesecond plate 84, whereby these terminals 6-8 are positioned along thedirection of thickness. Thereafter, the first plate 83 is retracted to aposition shown in FIG. 16C.

Then, resonators 2-5 are inserted one by one between the respectiveterminals 6-9, such that they are laterally displaced from centers ofthe terminals 6-9 as shown in FIG. 16C. At this time, since spacesbetween the terminals 6-9 are ensured by the terminal receiving grooves84a-84e of the second plate 84, the resonators 2-5 can be smoothlyinserted in the spaces without being hindered by the terminals 6-9.

Then, the first and third plates 83 and 85 are advanced and the secondplate 84 is retracted as shown in FIG. 16D, so that the resonators 2-5are integrally slid toward the centers of the terminals 6-9. Thus, bothside edges of all parts are held between the first and third plates 83and 85 to be positioned accurately in the lateral direction.

Thereafter, a plate spring 10 is inserted between the terminal 9 and thepresser 86, and all parts are compressed by the presser 86 and coveredwith a case 1. Then, the parts are ejected by a ejector 87 from below,to be integrally inserted in the case 1.

According to this embodiment, since a receiving portion for receivingthe inner parts is formed by the fixed guides 81 and 82 and thepositioning plates 83-85 which move laterally, the parts are heldcorrectly in the lateral direction, thereby facilitating insertion ofall parts in the case 1. Also, since the second positioning plate 84 hasthe terminal receiving grooves 84a-84e, the terminals 6-9 are heldcorrectly in the direction of thickness, thereby facilitating insertionof the resonators 2-5 between the terminals 6-9.

The present invention is not restricted to the aforementionedembodiments, but various modifications are available, as a matter ofcourse.

For example, though the parts are automatically inserted in the assemblyjig by the chuck hand in the first embodiment, the parts mayalternatively be inserted in the assembly jig manually.

Although the terminal plates, the plate springs and the cases aresupplied by the pallet in the aforementioned embodiment, the resonatorsmay also be supplied by the pallet. According to the aforementionedembodiment, the resonators are supplied from the element-supply unitwhich is independent of the pallet, for the reason that the resonatorsare generally varied with types of filters whereas the terminals, theplate springs and the cases are generally employed in common to varioustypes of the filters.

Further, the present invention is also applicable to a two-elementladder-tape filter or a ladder-type filter having five or more elements,in addition to the four-element ladder-type filter appearing in each ofthe aforementioned embodiment. The present invention is applicable toany electronic component, so far as it comprises elements which are heldbetween terminal plates under pressure and stored in a case.

Furthermore, the plate spring can be replaced by a rubber plate as acushion member. Also, the cushion member can be eliminated if at leastone of the terminal plates is made of a bent spring plate.

Moreover, the setting means in the present invention is not restrictedto the chuck hand, but can be replaced by any means as far as it can setand hold the case on the assembly jig.

Although the present invention has been described and illustrated indetail, it is clearly understood that the same is by way of illustrationand example only and is not to be taken by way of limitation, the spiritand scope of the present invention being limited only by the terms ofthe appended claims.

What is claimed is:
 1. A method of assembling an electronic componenthaving at least one element being held between terminal plates underpressure and stored in a case, said method comprising the stepsof:inserting said terminal plates into a receiving portion of a basemeans so as to align said terminal plates along a direction of thicknessthereof; inserting said element between said terminal plates in saidreceiving portion; compressing said terminal plates and said elementalong the direction of thickness so that an overall thickness of saidterminal plates and said element is smaller than an inner size of saidcase; and setting said case on said base means so that an opening ofsaid case corresponds to said receiving portion; and inserting saidterminal plates and said element from said base means into said casesimultaneously; wherein said terminal plates have lead portionsoutwardly protruding from said case, and wherein said base has leadportion receiving holes at a bottom of said receiving portion forreceiving said lead portions of said terminal plates so as to hold saidterminal plates.
 2. A method of assembling an electronic componenthaving at least one element being held between terminal plates underpressure and stored in a case, said method comprising the stepsof:inserting said terminal plates into a receiving portion of a base soas to align said terminal plates along a direction of thickness thereof;inserting said element between said terminal plates in said receivingportion; compressing said terminal plates and said element along thedirection of thickness so that an overall thickness of said terminalplates and said element is smaller than an inner size of said case; andsetting said case on said base so that an opening of said casecorresponds to said receiving portion; and inserting said terminalplates and said element from said base into said case simultaneously;wherein said electronic component has a cushion member for bringing saidterminal plates and said element into pressure contact with each otherto be electrically connected; and said method further comprising thestep of inserting said cushion member in said receiving portion so thatsaid cushion member is at an opposite side of one of said terminalplates with respect to said element.